1. Field of the Invention
The present invention relates to a probe of a probe card for measuring electric characteristics of a semiconductor device such as an LSI chip.
2. Description of the Background Art
A probe of a probe card for measuring electric characteristics of a semiconductor device such as an LSI chip is pressed against (overdrive) an electrode pad of the semiconductor device.
Conventionally, the probe is formed by sharpening an end of a constant-length metal line having electric conductivity and having a circular section, into a sharp configuration such as a square pyramid or a circular cone by mechanical polishing or electrolytic polishing.
FIG. 5 is a schematic view showing a perspective structure of the conventional probe. A probe 51 is formed by cutting a tungsten line having a diameter off approximately 0.1 to 0.5 mm into a predetermined length and sharpening an edge part 53 of a contact part 52 by mechanical polishing or electrolytic polishing.
FIG. 6 is a schematic view showing a front and side face sectional structure of the end of the conventional probe. The edge part of the contact part has a sharp configuration such as a square pyramid shown in FIG. 6A or a circular cone shown in FIG. 6B. While the contact part 52 having such configuration is pressed against the electrode pad many times, the configuration of the edge part 53 is deformed and changes in shape.
Thus, according to the conventional probe, the contact part has the sharp edge part having the configuration such as the square pyramid or the circular cone, which causes not only a measurement defect because of the configuration variation, but also a measurement defect because of attachment of a foreign substance such as shavings of the electrode pad or aluminum powder generated by the contact with the electrode pad.